1. Field of the Invention
The invention concerns a process for synthesizing hydrocarbons by dehydration of acyclic alkanols and more particularly concerns the synthesis of hydrocarbon fuel and lubricant compositions from methanol or trimethyl phosphate.
2. Brief Description of the Invention
World attention has now focused upon the need for development of economical processes for the synthesis of hydrocarbon fuels and lubricants from readily available raw materials. Many of the previously suggested synthetic schemes are currently under renewed investigation to develop or improve a means whereby independence from the traditional petroleum sources of hydrocarbon fuels and lubricants can be achieved.
The dehydration of alkanols having at least 2 carbon atoms, to obtain mixtures of hydrocarbons was reported prior hereto; see for example U.S. Pat. Nos. 2,373,475 and 3,501,546. The former patent disclosure is particularly significant since the patentee dehydrated a wide range of acyclic alkanols with phosphoric acid to obtain hydrocarbon mixtures, but expressly excluded methanol as a starting material in his process of dehydration. In U.S. Pat. No. 1,895,529 the patentee taught dehydration of acyclic alkanols with oxide dehydrating agents such as the oxides of aluminum and thorium to obtain hydrocarbons. However, in regard to the dehydration of methanol, the patentee stated that the product obtained by his process was dimethyl ether and not a hydrocarbon which would be useful as a combustible fuel or lubricant.
Subsequently, Grosse et al. disclosed in U.S. Pat. No. 2,492,984 that methanol could be converted to branched chain hydrocarbons under specific temperature conditions in the presence of a dehydrating agent such as zinc chloride. Although nebulous, there is a teaching which could be construed as equating phosphoric acid to the zinc chloride in this reaction, but the patentee provided no working examples or details of procedure for one skilled in the art to follow and it would appear that any product mixture obtained would not be expected to include aromatics or cycloaliphatic compounds, a desirable fuel composition component.
More recently, U.S. Pat. Nos. 2,793,241 and 2,744,151 have described the conversion of methanol to hydrocarbon waxes by heating under super-atmospheric pressures in the presence of cobalt or molybdite catalysts.
Methanol is a relatively inexpensive compound, available in relative abundance. By the process of my invention it may be readily converted to hydrocarbon compositions which are useful fuels and lubricants. The process of the invention is particularly advantageous in that it produces high product yields, may be carried out under atmospheric pressure, requires relatively little energy input, uses reagents which are relatively abundant, yields a pure product which is readily separated from the reaction mixture without the use of expensive and complicated separatory techniques and is relatively non-hazardous to practice.
Subsequent to my invention, the process of the invention was disclosed by me in J.C.S. Chem. Comm., 1974, page 397.